What is a Heat Exchanger?
Heat exchangers are used in both heating and cooling processes to transfer heat expended from one process or place for use in another. They enable the thermal energy from a liquid or gas to pass to another liquid or gas without the two having to come into direct contact. Common everyday examples include domestic radiators (which transfer heat from a boiler to a room) and car radiators (which takes heat away from the engine).
Types of Heat Exchanger
Two of the most common types are Plate Heat Exchangers and Tubular Heat Exchangers, and within these broad categories are variations of models to suit a range of functions, results, and environments. Therefore, it is always advisable to consult a specialist who can explain all appropriate options and design tailored solutions to suit all requirements.
For products that are relatively low in viscosity and without particles, the plate heat exchanger design is ideal as it uses many thin, corrugated plates packed inside a frame with the product and service fluid flowing through alternate herringbone-arranged channels. This allows the fluid to flow in small passages over a large surface area, providing a high level of turbulence to increase the speed and efficiency of heat transfer rates.
Double tube heat exchangers have one tube concentrically positioned within a larger tube. The product can flow unrestricted through the inner tube while the service fluid flows through the surrounding shell, making it the ideal heat exchanger for viscous products
Multitube heat exchangers contain multiple tubes that carry the product through the interior tubes while the service fluid flows through the surrounding shell. Its versatile design is ideal for use in a wide range of industries and applications.
Comprising of three or four concentric tubes, the annular space design allows the product to flow through the tube’s annular space while the service fluid passes through both the inner and outer tubes. This design ensures even heating or cooling and the inner tube is removable, providing easy access for inspection.
Scraped surface heat exchangers are specifically designed to overcome issues caused by fouling and by-product production and high viscous fluids that will cause heat transfer rates to drop. The internal mechanism of a scraped surface heat exchanger keeps the product moving and at a uniform heat. This keeps surfaces cleaner for longer and reduces the opportunity for fouling, ensuring maximum efficiency and energy use.
HRS corrugated tube heat exchangers are designed so that the constant swirling of the fluid in the tube prevents sediment and clogging when used with certain materials like digestate.
|AS 3 Series
The Benefits and Pitfalls in Heat Exchanger Design
With so many design options available, it is vital to understand all the critical factors that will impact any choice of heat exchanger. In addition to the type of application and environment a heat exchanger will be subjected to, other considerations such as running costs, maintenance and cleaning over the full life of the plant can eat into any capital savings made at the time of purchase. Space, budget, and investment rationalisation are also important influencing factors, and this is where a heat exchanger expert can design the most appropriate solution for any requirement.
Getting it right
- Energy efficiency
- Cost savings
- Manpower reduction
- Cleaner, more sanitary, and hygienic production
- Realise value from by-products
- Waste reduction
Getting it wrong
- Consequences of fouling
- Avoidable and unnecessary expenses
- Degradation of performance and product quality
- Reduced capacity
- Poor energy efficiency
For more information visit our Resources on:
- Heat Transfer Fundamentals
- How to Design a Tubular Heat Exchanger?
- Top Tips for Specific Types of Heat Exchanger Fouling